Laboratory strains of Aedes aegypti are Competent to Brazilian Zika virus

Abstract

Since the Zika outbreaks are unprecedented human threat in relation to congenital malformations and neurological/autoimmune complications as well as its high potential to spread in regions presenting the vectors, improvements in mosquito control is a top priority. Thus, Aedes aegypti laboratory strains will be fundamental to support studies in different research fields implicated on Zika-mosquito interactions which are the basis for the development of innovative control methods. In this sense, we determined the main infection aspects of the Brazilian Zika strain in reference Aedes aegypti laboratory mosquitoes.\n\nWe orally exposed Rockefeller, Higgs and Rexville mosquitoes to a Brazilian ZIKV (ZIKVBR) and qRT-PCR was applied to determine the infection and dissemination rates, and viral levels in mosquito tissues as well as in the saliva. The ZIKVBR kinetics was monitored during the infection in Rockefeller mosquitoes. Rockefeller strain was the most susceptible at 7 days post-infection but all strains presented similar infection levels at 14 days post-infection. Although variations in the saliva detection rates were observed, we confirmed that ZIKVBR was present in saliva from Rockefeller, Higgs and Rexville females at detectable levels at 14 days post-infection. The ZIKVBR kinetics in Rockefeller mosquitoes showed that the virus could be detected in the heads at 4 days post-infection but was more consistently detected late in infection. The viral levels peaked at 11 days post-infection in the mosquito bodies, remaining stable until 14 days post-infection, in contrast to the heads, where the mean viral levels only peaked at 14 days post-infection.\n\nOur study presents the first evaluation on how Brazilian Zika virus behaves in reference Aedes aegypti strains and shed light on how the infection evolves over time. Vector competence and basic hallmarks of the ZIKVBR development were revealed in laboratory mosquitoes. This study provides additional information to accelerate studies focusing on ZIKV-mosquito interactions.